/*
 * Copyright 2017 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.util.internal;

import java.lang.reflect.AccessibleObject;

public final class ReflectionUtil {

  private ReflectionUtil() {
  }

  /**
   * Try to call {@link AccessibleObject#setAccessible(boolean)} but will catch any {@link
   * SecurityException} and {@link java.lang.reflect.InaccessibleObjectException} and return it. The
   * caller must check if it returns {@code null} and if not handle the returned exception.
   */
  public static Throwable trySetAccessible(AccessibleObject object, boolean checkAccessible) {
    if (checkAccessible && !PlatformDependent0.isExplicitTryReflectionSetAccessible()) {
      return new UnsupportedOperationException("Reflective setAccessible(true) disabled");
    }
    try {
      object.setAccessible(true);
      return null;
    } catch (SecurityException e) {
      return e;
    } catch (RuntimeException e) {
      return handleInaccessibleObjectException(e);
    }
  }

  private static RuntimeException handleInaccessibleObjectException(RuntimeException e) {
    // JDK 9 can throw an inaccessible object exception here; since Netty compiles
    // against JDK 7 and this exception was only added in JDK 9, we have to weakly
    // check the type
    if ("java.lang.reflect.InaccessibleObjectException".equals(e.getClass().getName())) {
      return e;
    }
    throw e;
  }
}
